Kirby + DK teams; stay low, avoid taking damage, save DK from chaingrabs, try to upthrow and forward throw characters a lot
For grab combos, DK D-Throw to Kirby U-smash is fast and solid. Kirby F-throw to DK jumping Giant Punch with good timing (try to get it on the release of the throw), Kirby D-throw to DK Full jump D-air to followups, DK D-throw or cargo to swallowcide.
A neat thing to do is to have DK f-smash and whiff, suck him up as he lags, and spit him out into their counterattack. DK is heavy enough to do 18% :o
Otherwise, you're the backup plan for the matchup. Your goal is safe 0-50% damage strings and tie-up so DK can land his power combos. U-throw is great at higher percents for taking one player out of the picture for a hot second, because it pops them up so high. Since DK is great at spacing and air pressure, just stay low to give him free reign and beat stuff up a lot, and use your tinyness to fit into spaces and add to the pressure. Its a buff team.
You can also use rock to save DK off the edge if he gets into something sticky
teching ftw